Review Article

The Importance of Velocity Acceleration to Flow-Mediated Dilation

Figure 2

Determination of Shear Rate (γ). As fluid particles “travel” parallel to the vessel wall, their average velocity increases from a minimum at the wall to a maximum value at some distance from the wall, resulting in a gradient of velocities. The actual shear rate at the vessel wall is determined by shape of the velocity profile. Shear stress-induced deformation of the endothelial cells is detected by mechanoreceptors on the cell membrane.
589213.fig.002a
(a) High parabolic velocity
589213.fig.002b
(b) Low parabolic velocity
589213.fig.002c
(c) Plug velocity